1. Field of the Invention
The present invention relates to a cylinder for processing sheets of printing material. Such cylinders are used for punching and/or scoring and/or perforating the sheets. A printing press having the cylinder, is also provided.
German Patent DE 198 14 966 C2, corresponding to U.S. Pat. No. 6,651,539, describes a cylinder which includes a clamping channel, a tool plate for punching and/or scoring and/or perforating the sheets, a support plate for carrying the tool plate and a first clamping system for clamping the support plate. In the above-mentioned patent, the tool plate is referred to as a base sheet and the support plate is referred to a base plate. Furthermore, the cylinder includes a first holding device for holding a front end of the support plate, a second holding device for holding a rear end of the support plate, a third holding device for holding a front end of the tool plate and a fourth holding device for holding a rear end of the tool plate. The first holding device and the second holding device together form the first clamping system which is referred to as a blanket holding device in the above-mentioned patent. The third holding device and the fourth holding device are disposed on the support plate and are referred to as fastening bars in the above-mentioned patent.
It is a disadvantage of the cylinder of the prior art that the tool plate cannot be clamped onto it with accurate register. The fastening bars are comparatively unstable, which results from their configuration on the support plate and opposes improved register accuracy.
2. Summary of the Invention
It is accordingly an object of the invention to provide a cylinder for processing sheets of printing material on which a tool plate can be positioned with accurate register and a printing press having the cylinder, which overcome the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type.
With the foregoing and other objects in view there is provided, in accordance with the invention, a cylinder for processing sheets of printing material. The cylinder comprises a clamping channel having a central region and edge regions. A tool plate punches and/or scores and/or perforates the sheets. A support plate carries the tool plate. A first clamping system for clamping the support plate has a first holding device for holding a front end of the support plate and a second holding device for holding a rear end of the support plate. The first holding device and the second holding device are disposed in the edge regions. A second clamping system for clamping the tool plate has a third holding device for holding a front end of the tool plate and a fourth holding device for holding a rear end of the tool plate. The third holding device and the fourth holding device are disposed in the central region.
The configuration of the third holding device and the fourth holding device in the central region makes it possible for the third holding device and the fourth holding device to be disposed separately from the support plate. This separate configuration makes a solid and stable configuration of the third holding device and the fourth holding device possible. The solid and stable configuration is in turn advantageous with regard to clamping the tool plate onto the cylinder with accurate register.
As a result of the fact that the third holding device and the fourth holding device together form the second clamping system, it is possible to clamp the tool plate in a manner which is independent of the clamping of the support plate, which in turn is advantageous with regard to the register accuracy. The tool plate can be not only held firmly through the use of the second clamping system, but can also be clamped, that is to say can be tautened in the circumferential direction of the cylinder.
In accordance with another feature of the invention, the first holding device and the second holding device are rotatably mounted clamping shafts.
In accordance with a further feature of the invention, the third holding device and the fourth holding device are clamping devices which include in each case a first clamping jaw and a second clamping jaw.
In accordance with an added feature of the invention, the clamping devices include in each case an eccentric shaft for adjusting the first clamping jaw toward and away from the second clamping jaw. The adjustment takes place during clamping and release of the tool plate.
In accordance with an additional feature of the invention, the second clamping system includes a gear mechanism for moving the fourth holding device toward and away from the third holding device. The movement takes place during release and clamping of the tool plate. This gear mechanism is preferably a worm gear mechanism.
In accordance with yet another feature of the invention, the second clamping system includes a joint for guiding the fourth holding device toward and away from the third holding device. The guidance takes place during release and clamping of the tool plate. This joint can be a rotary joint, about which the fourth holding device can pivot, and is preferably a linear thrust joint, that is to say a linear guide.
In accordance with yet a further feature of the invention, the third holding device is equipped with register pins for positioning of the tool plate with accurate register.
In accordance with yet an added feature of the invention, the cylinder has a basic body with a fastening head for fastening the second clamping system. The fastening head protrudes into the central region.
In accordance with yet an additional feature of the invention, the second clamping system has a carrier plate for carrying the third holding device and the fourth holding device. The carrier plate is fastened to the fastening head. The carrier plate is preferably fastened to the fastening head through the use of screws.
In accordance with still another feature of the invention, the fastening head is configured to be compatible with a covering hood for covering the central region. As a result, the second clamping system can optionally be fastened to the fastening head for a first cylinder equipment state, and the covering hood can be fastened to the fastening head for a second cylinder equipment state.
With the objects of the invention in view, there is also provided a printing press, comprising the cylinder configured according to the invention.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a cylinder for processing sheets of printing material and a printing press having the cylinder, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.